Axle or shaft.



M. c. SCHWAB. AXLB 0B SHAFT. APPLICATION FILED JUNE 6, 1910.

' I Patented Sept. 12, '1911.

E/ wel UNITED 'STATES PATENT OFFICE.

MARTIN C. SCHWAB, 0F CHICAGG, ILLINOS.

AXLE OB. SHAFT.

Specification of Letters Patent.

Patented sept. la, ieu.

Application filed .Tune 6, 1910. Serial No. 565,37.

To all wlw/m 'it may concern:

Be it knoiynthat I, A'lan'rix C. Sorivim, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Axles or Shafts, of which the following is a `specitica-tion.

My invention relates to improvements in.

axles or shafts, and has especial. reference to lsafety axles for vehicles, such as locomosociated.

Another object of my invention is to provide an indicating device, associated with the ivorking and safety axles, that will, readily render obvious the fact that the Working axle has become weakened or partially disabled so that repairs 4may be made before entire ydisablement of the Working axle has occurred.

lt is a Well known fact that if steelor iron is called upon to bear or to withstand a. strain orstress nearly equal to its capacity for a protracted length. ottime, that it becomes fatigued, and is, forthat reason, liable to fracture. The molecules of iron, er steel, of which the axle composed, become crystallized, or rearranged in a radial direction or other such manner as' to cause considerable loss of strength of the iron or steel. :This results from hard work or overstrain of the material and lsag and finally fracture is liable to be produced vby subsequent sudden concussion or extra strain, Without warning and Without any means for ascertaining the condition of the axle untill complete fracture has occurred.

My invention provides a safety axle, to

be preferably contained Within a hollow, primary axle, and which is not called upon normally to do any of the 'Work that 'is 1ncumbent upon the primary axle .until after the occurrence ofwveakness or fracture of the primary axle, so that the safety axle will not be fatigued or crystallized, and is, therefore, Well able to withstand the strain impressed upon it in the event of fracture of the primaryaxle.

In the drawing, Figure l is a plan view of an ordinary truck ofI a railway car;

Fig. :2 .is an enlarged section through one of the Wheels and axle of the truck; Fig. 3 is a section taken on line 3-3 of Fig. 1, showing the indicating device; and F ig. l is a section on line t-et of Fig.- l showing a means for holding the safety axle to pre vent rotation' during normal operation.

5 is a. hollowvprimary axle 'to which the Wheels 6 and 7 are attached at its respective ends. The axle isprovided with bearings,

8 and 9. The primary axle is longitudinally hollow, and contains on its inside the secondary or safety axle. 'in the ordinary operation of the device the safety axle, 10, is held stationary and is not called upon to bear any of the strain or to perform any of the yWork incumbent upon the vprimary axle, 5. .It lies neatly inside of the primary axle, and no stress or strain is imparted to it, While the primary axle is inoperative condition. By this arrangement, I pren serve .the safety axle in condition free from y fatigue and from the eect of4 crystallization and consequent Weakness or deteriorau tion which affects the primary axle.

In the' event of partial or complete fracture of the primary'axle, the secondary or safety' axle will bear the lburden and hold 'the parts inrelative psitions, so that the car maybe safely carried to itsdestinat-ion- Without danger of breaking down vof the axle, and Wrecking of the car or train. Then the car has reached its destination, 'a new primary axle may besubstituted for the fractured one. n

It is desirable that the Safety shaft, l0, be heldto prevent its rotation. It isv also desirable that some means be provided to indicate the fact that the said shaft has been rotarily displacedas `evidence that the normally Working axle has been partially or wholly -disabled'so that repairs may be made before thevvorking shaft be' Wholly incapacitated. l A

A.- partial fracture or other weakening of be evidenced by the rotatively with, an extended end,- 13, which is secured toa ixedpart of the truck as at 14, by the bolt, 15.' shafts is suiiicientto cause rotation of the Vinterior or safety shaft. y

I indicate the -rotary displacement ofthe interior or safety shaft 'relative to the fixed parts of the frame, by .maln'ng an indicat 4if-Ling-niark, 16, shown as an arrow, on the shaft and a similar mark, 17, on a fixed `part of the frame. Displacementof the register of marks 16 and 17 will indicate 4that the marking, shaft has been weakened, fractured, or partially fractured, and that y immediate repairs should be made'. If the damage has been so great as to cause contiuued-rotation of the safety shaft, the fricxtion between the clamp-and' shaft will engender suiiicient heat toignte the lubricating dope"7 within the box and thereby indicate the condition.

While my invention may be used for other purposes than in railway vehicles, it is more particularly adapted for this use as a' means for the prevention of the-disastrous results that may follow the 'damj age to the primary axle.

The clamp is provided.

Abnormal friction between the Having thus described my invention what I claim is; 4 1. In combination, 'a hollow, primary lworking axle, and a safety, loose idle axle therein, normally having no supporting relation-with said working axle.

2. In combination, a hollow, primary working axle, bearings at each end, traction wheels therebetween xed to said axle, and a safety idle axle within said working axle extending beyond the bearings thereof, and normally having no supporting relation with said working axle. y

3. In combination, a ,hollow primary working axle, a safety idle axle within said working axle, andmeans for yieldingly restraining said safety loose axlefrom rotation,"normally having no supporting relation with said working'axle.

4. In combination, a hollow primary working'axle, a safety idle axle within said working axle, means for yieldingly restraining said 'safety axle from rotation, and means for indicating rotary movement of said safety axle.

5. In combination, a hollow primary working axle, bearings therefor, a safety idle axle within said' working axle, Fand means for supporting said safety axle in event of inability of said working axle to alone vsustain its operating load.

In testimony whereof I hereunto set my hand `in the presence of two witnesses.

MAB/IIN C. SCHWAB.

In the presence of- W. LINN ALLEN, MARY F. ALLEN. 

